I think this one looks the cleanest:

my( $var1, $var2 ) = (
    subroutine0_with_return_value(),
    subroutine1_with_return_value()
);
[download]

but I'm lazy and I find that:

my $var1 = sub_w_ret_val1();
my $var2 = sub_w_ret_val2();
[download]

is the easiest to think through, especially when assigning several return values.

but I was taught that:

public static void main(){
    int var1, var2;
    //declare more variables here
    var1 = sub_w_ret_val();
    var2 = sub_w_ret_val();
}
[download]

(note the language change)

was the correct method for declaring variables.

while I'm not saying I find the third is the best method for declaring and using variables, I sometimes find myself doing the Perl (is it Perl or perl?) equivalent.

my $file1, $file2
my $var1, $var2

$var1 = &sub_w_ret_val();
$var2 = &sub_w_ret_val();
[download]

any way, that's my two cents on code writing optimization.